/Engine/Source/Runtime/Engine/Public/BoneContainer.h
Map skeleton bone index to compact pose index
the compact pose bone index for the specified skeleton pose bone index. Returns an invalid index if the compact pose does not include the specified skeleton bone.
[FCompactPoseBoneIndex](API\Runtime\AnimationCore\FCompactPoseBoneIndex) GetCompactPoseIndexFromSkeletonPoseIndex ( const [FSkeletonPoseBoneIndex](API\Runtime\AnimationCore\FSkeletonPoseBoneIndex) & SkeletonIndex ) const